This invention relates to improvements in tracheotomy tubes.
This invention is directed toward the problem of being unable to produce audible laryngeal voice, and thus, the inability to speak, that confronts individuals whose breathing is provided mechanically by a respirator which is connected to a cuffed tracheotomy tube inserted into the trachea of a wearer below the level of the vocal cords. The cuff on the tracheotomy tube is inflated, for example, with air, so that the cuff seals substantially fluid tight against the wall of the trachea. The purposes of the inflated cuff include: to protect against leakage of saliva and other secretions around the tracheotomy tube and into the lungs; and, to prevent the air being delivered under pressure from the respirator through the tracheotomy tube to the lungs and exhalation from the lungs from escaping around the tracheotomy tube and out through the mouth and nose of the wearer. In other words, the inflated cuff provides a closed mechanical respiratory system that completely bypasses the upper airway above the level of the tracheotomy tube, including the vocal cords. The side effects of this include the elimination of exhaled airflow upward through the vocal cords. Of course, this eliminates voice production and audible speech.
Currently, there are only two available options for individuals being mechanically ventilated via a cuffed tracheotomy tube to produce audible voice and speech with their own vocal cords. The first of these options is described in O. Hessler, M. D., K. Rehder, M. D., and S. W. Karveth, MC, U. S. A., xe2x80x9cTracheostomy Cannula for Speaking During Artificial Respiration,xe2x80x9d Anesthesiology, vol. 25, no. 5, pp.719-721 (1964). There is no known commercially available device constructed as described in Hessler, et al.
The second option is a so-called xe2x80x9ctalking tracheotomy tube,xe2x80x9d which is a conventional cuffed tracheotomy tube manufactured with an 8-10 French conduit extending along its length. The distal end of this conduit terminates above the level of the inflated cuff. The proximal end of this conduit is connected to a source of, for example, compressed air. Examples of such a device are manufactured by Sims Portex, Inc., and Bivona Surgical Inc. The wearer of such a device is able to stop and start the flow of compressed air to the distal end of this conduit, thereby enabling the stopping and starting of the flow of air upward through his or her vocal cords, enabling the wearer to produce speech. This speech airflow is completely independent of the respiratory airflow through the tracheotomy tube. Such talking tracheotomy tubes have been available for several years, but are not in widespread use, perhaps owing to numerous mechanical limitations.
A ventilator-dependent patient breathing through cuffed tracheotomy tube is unable to produce audible voice with his or her vocal cords because the cuff of the tracheotomy tube he or she wears prevents exhalations from going around the lower end of the tube and upward through the vocal cords. This situation continues until the wearer""s condition improves sufficiently that the cuff on the tracheotomy tube can be deflated so that exhaled air can pass around the tracheotomy tube and up through the wearer""s vocal cords, mouth and nose, permitting audible vocal cord vibrations for speech.
The invention alleviates this situation. When coupled to a respirator with its cuff inflated, a valved, cuffed tracheotomy tube system according to the invention directs air on the inhalation cycle of the respirator to the lungs. Exhalations are directed by the valved, cuffed tracheotomy tube system according to the invention to the upper airway, permitting vocal cord vibration and audible laryngeal speech.
According to one aspect of the invention, an outer cannula has a first port for orienting outside the neck of a wearer, a second port for orienting within the trachea of the wearer, a first passageway coupling the first port to the second port to permit the flow of gases from the first port to the second during inhalation by the wearer and from the second port during exhalation by the wearer, and a third port between the first and second ports. An inner cannula is configured for insertion into the first passageway via the first port when the wearer desires to be able to exhale through his or her pharynx. The inner cannula includes a fourth port for orienting adjacent the first port, a fifth port for orienting adjacent the second port and a second passageway coupling the fourth port to the fifth port to permit the flow of gases from the fourth port to the fifth during inhalation by the wearer and from the fifth port during exhalation by the wearer. A valve controls flow through the third port. The valve assumes a first orientation to permit flow from the first port to the second port when the first port is at a higher pressure than the second port, and a second orientation to permit flow from the second port through the third port when the second port is at a higher pressure than the first port.
Illustratively according to the invention, the valve includes a movable member and a seat. The movable member moves away from the seat to permit flow from the fourth port to the fifth port when the fourth port is at a higher pressure than the fifth port, and seats against the seat to impede flow from the fifth port through the fourth port and promote flow from the fifth port through the third port when the fourth port is at a lower pressure than the fifth port.
Illustratively according to the invention, the seat is provided in the second passageway.
Alternatively illustratively according to the invention, the seat is provided in the first passageway.
Additionally according to the invention, the valve includes a movable member and a seat. The movable member moves toward the seat to impede flow from the fourth port through the third port when the fourth port is at a higher pressure than the fifth port, and moves away from the seat to permit flow from the fifth port through the third port when the fourth port is at a lower pressure than the fifth port.
Further illustratively according to the invention, the outer cannula includes an inflatable cuff between the second and third ports and a third passageway for introducing an inflating fluid into the cuff in situ in the trachea of the wearer to impede the flow of fluids between the cuff and the trachea when the cuff is inflated.
Additionally illustratively according to the invention, the outer cannula includes a flexible member for covering the third port.
Illustratively according to the invention, the flexible member and the outer cannula include complementary first and second attachment members, respectively, for attaching the flexible member to the outer cannula. The second attachment member provides an attachment point located within the third port for attachment of the first attachment member to the second attachment member at the attachment point.
Alternatively illustratively according to the invention, the flexible member comprises a flexible membrane having a slit in it.
Alternatively illustratively according to the invention, the flexible member comprises a flap for covering the third.
According to another aspect of the invention, a tracheotomy cannula has a first port for orienting outside the neck of a wearer, a second port for orienting within the trachea of the wearer and a first passageway coupling the first port to the second port to permit the flow of gases from the first port to the second during inhalation by the wearer and from the second port during exhalation by the wearer. The cannula includes a portion formed from a thermoplastic material having a first, generally curved orientation when said portion is maintained substantially below body temperature and a second, somewhat inverted L-shaped configuration when said portion is warmed substantially to body temperature.
According to another aspect of the invention, a tracheotomy cannula has a first port for orienting outside the neck of a wearer, a second port for orienting within the trachea of the wearer and a first passageway between the first port and the second port to permit the flow of gases from the first port to the second during inhalation by the wearer and from the second port during exhalation by the wearer. The cannula includes a portion formed from a relatively more flexible material. A stylet is formed from a relatively less flexible material. The stylet has a generally curved orientation. The tracheotomy cannula has a somewhat inverted L-shaped configuration when the stylet is not inserted into the first passageway and a generally curved orientation when the stylet is inserted into the first passageway.